JPH0890Y2 - Collet chuck - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a collet chuck that supports an annular work with an inner diameter certificate.

(Conventional Technology) As a conventional technology, there is a structure shown in FIG.

In FIG. 4, reference numeral 1 denotes a mounting board coaxially fixed to the main shaft, and the support 2 is coaxially bolted and fixed to the mounting board 1.

The support body 2 has a large-diameter flange portion 3 and a small-diameter shaft portion 4 on the left and right integrally and coaxially, and is bolted and fixed to the mounting board 1 at the flange portion 3.

The shaft portion 4 has a mandrel 5 formed on the right side thereof, and a collet main body 6 is fitted to the mandrel 5.

The mandrel 5 has a front taper shaft portion 5a, a fitting shaft portion 5b of equal diameter, and a rear taper shaft portion 5c, which are sequentially formed from the right end to the left, and each front taper hole shaft portion 5a and Rear taper shaft
Both 5c are formed on a taper shaft whose diameter gradually increases toward the left.

Further, the collet main body 6 is formed by forming a pair of rear tapered holes 6c and front tapered holes 6a that expand leftward and rightward both ends of the inner circumference of the cylindrical body to the left, and the left and right central portions are fitted with equal diameters. Aperture 6b
The first slit 6d extending in the circumferential wall from the left end to the front of the right end and the second slit 6e extending from the right end to the front of the left end are alternately formed in the circumferential direction to form the circumferential wall in the circumferential direction. Divided into multiple pieces.

Then, the collet main body 6 is fitted to the outer periphery of the mandrel 5, and the front and rear tapered holes 6a, 6c and the fitting hole 6b are fitted to the front and rear tapered shafts 5a, 5c and the fitting shaft part. Contact 5b.

A ring-shaped centering stopper 7 and a ring-shaped front stopper 8 are fitted on the outer periphery of the left side of the shaft portion 4 so as to be swingable via elastic bodies 9 and 9 made of O-rings.

The centering stopper 7 has a pair of contacts 7a, 7b extending in the radial direction on both left and right sides thereof, which are formed so as to project out of phase with each other by 90 degrees in the circumferential direction.
On the front surface 3a of the
Contact 8b.

Reference numeral 10 denotes a cylindrical holding case fixed to the outer circumference of the flange portion 3 of the support body 2, surrounding the outer circumferences of the centering stopper 7 and the front stopper 8, and forming a small-diameter locking portion 10a at the right end. An O-ring 11 is interposed between the locking portion 10a and the step formed on the outer periphery of the front stopper 8 to prevent the aligning stopper 7 and the front stopper 8 from moving to the right.

Denoted at 12 is a pressing tool, in which the operating rod 13 is slidably fitted to the shaft center portion of the support 2 described above, and a large-diameter pushing piece 14 is fixed to the right end thereof, and this pushing piece 14 is used as the collet main body 6 It comes into contact with the right end surface of.

The left end of the operating rod 13 is connected to a draw bar (both not shown) that is moved in the left-right direction by a hydraulic cylinder.

Then, the work 15 having the spline hole 15a formed therein is fitted to the collet main body 6, and the rear surface 15b is brought into contact with the front surface 8a of the front stopper 8 to move the collet main body 6 to the left via the operating rod 13. When the work 15 is moved and expanded, the work 15 is supported by the collet main body 6 by the inner diameter certificate, and the centering stopper 7 is automatically centered so that the front surface 8a of the front stopper 8 is substantially aligned with the rear surface 15b of the work 15. The workpiece 15 is abutted with a uniform pressure, so that the work 15 is firmly supported by the support 2.

(Problems to be solved by the invention) In the above-mentioned conventional one, since the outer circumference of the collet main body 6 is formed to have the same diameter over the entire length, when the collet main body 6 is expanded and the work 15 is supported, As shown in FIG.
The outer peripheral portions of the left and right ends of the collet main body 6 corresponding to the front and rear taper shaft portions 5a and 5c of the mandrel 5 are spline holes of the work 15.
Firmly abut the left and right ends of the inner circumference of 15a, and
There was a defect that the tooth top surfaces 15c, 15c at the left and right ends of the were damaged.

An object of the present invention is to obtain a novel collet chuck that solves the above drawbacks.

(Means for Solving the Problems) The present invention is configured as follows in order to achieve the above object.

That is, the cylindrical body is divided into a plurality of pieces in the circumferential direction by leaving a plurality of slits extending in the axial direction while alternately leaving one end portion and the other end portion, and at both end portions of the inner circumference of the cylindrical body from one end to the other end. A collet main body formed by forming a pair of taper holes that expands is provided, and a core shaft having a pair of taper shaft parts that expand from the front end toward the rear part is provided at two positions in the axial direction of the front end part,
In a collet chuck having a collet main body fitted on the mandrel, each taper hole of which is brought into contact with each taper shaft portion of the mandrel, and a pressing tool for pressing the collet main body in the rearward direction of the mandrel, is provided. The outer diameter of both ends of the main body of the collet in which is located is slightly smaller than the outer diameter of the axial center portion of the main body of the collet.

The outside diameter of both ends of the collet main body where the above taper holes are located is 0.01 mm compared to the outside diameter of the center portion of the collet main body in the axial direction.
It is preferably formed to have a small diameter.

(Operation) Since the present invention is configured as described above, when the work is fitted around the outer periphery of the collet main body and the collet main body is pressed and moved in the rearward direction of the mandrel by the pressing tool, the respective tapered holes of the collet main body are The collet main body is expanded to a large diameter by being pressed by each taper shaft portion of the mandrel, and its outer peripheral surface comes into pressure contact with the inner peripheral surface of the work.

In this case, in the outer periphery of the collet main body, the outer peripheral surface of the center in the left-right direction first contacts the center of the inner periphery of the work, and then both ends of the collet main body are elastically deformed outward in the radial direction so that the outer peripheral surface is inside the work. It will contact both left and right ends of the circumference.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In the drawings, FIG. 1 is a sectional view of a main part of a collet chuck showing an embodiment of the present invention, FIG. 2 is a sectional view mainly of a collet chuck, and FIG. 3 is a side view thereof.

In addition, in FIG. 1, the same reference numerals as those in FIG.
Since the structure is substantially the same as that of the figure, its description is omitted.

In FIG. 1, 16 is mainly a collet, and is formed by a pair of rear taper hole 19 and front taper hole 17 that expand the inner circumference of the cylindrical body to the left at both left and right ends, and the center of the inner diameter at the left and right. A portion is formed in the fitting hole 18 having an equal diameter, and a first slit 20 extending from the left end to just before the right end and a second slit 21 extending from the right end to just before the left end are alternately arranged in the circumferential direction on the peripheral wall. It is formed to divide the peripheral wall into a plurality of pieces in the circumferential direction, and these have substantially the same structure as the above-described conventional collet main body 6.

The present invention, as shown in FIG.
It is characterized in that the left and right outer peripheral ends are formed into small-diameter and annular step portions 16b, 16b.

That is, the step portions 16b and 16b are formed by cutting the left and right outer peripheral ends of the collet main body 16 in which the front and rear tapered holes 17 and 19 are located, and the outer diameter D2 thereof is set to the outer diameter D1 of the outer periphery 16a of the center portion in the left-right direction. 0.01m
m Form to a small diameter.

 Next, the operation and effect of the above embodiment will be described.

The work 15 is fitted to the outer periphery of the collet main body 16, and the rear surface 15b of the work 15 is brought into contact with the front surface 8a of the front stopper 8.

Next, when the pressing tool 12 is moved to make it and the collet main body 16 is pressed and moved leftward (rearward direction) with respect to the mandrel 5,
The taper holes 17 and 19 of the collet main body 16 are pressed by the taper shaft portions 5a and 5c of the core shaft 5, the collet main body 16 is expanded to a large diameter, and the outer peripheral surface thereof is the inner peripheral surface of the work 15, that is, It comes into pressure contact with the spline hole 15a.

In this case, in the collet main body 16, first, the outer peripheral surface of the central portion in the left-right direction is in pressure contact with the central portion of the spline hole 15a, and then both ends of the collet main body 16 are elastically deformed outward in the radial direction to form the step portions 16b, 16b. It comes into pressure contact with the left and right ends of the spline hole 15a.

As a result, the outer periphery of the collet main body 16 is pressed against the spline hole 15a of the work 15 with a substantially uniform pressure in its entire axial direction.
The tooth top surface 15c of the spline hole 15a is not damaged.

(Effects of the Invention) As is clear from the above description, the present invention can securely support the work with the inner diameter certificate without damaging the inner peripheral surface of the work, and the structure thereof is simple and inexpensive to obtain. There is an effect that can be done.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a collet chuck showing an embodiment of the present invention, FIG. 2 is a sectional view mainly of a collet, FIG. 3 is a side view thereof, FIG. 4 is a sectional view showing a conventional example, and FIG. The figure is an enlarged cross-sectional view of the main part thereof. 1: Mounting board, 2: Support, 3: Flange part, 3a: Front part, 4: Shaft part, 5: Mandrel shaft, 5a: Front taper shaft part, 5b: Fitting shaft part, 5c: Rear taper shaft part , 6: Collet mainly, 7: Alignment stopper, 7a, 7
b: contactor, 8: front stopper, 8a: front surface, 8b: rear surface, 9: elastic body, 10: holding case, 10a: locking portion, 11: O-ring, 12: pressing tool, 13: operating rod, 14: push piece, 15: work, 15a: spline hole, 15b: rear surface, 15c: tooth top surface, 16: collet main body, 16a: outer periphery of the center in the left-right direction, 16b: step, 17: front taper hole , 18: fitting hole, 19: rear taper hole, 20: first slit, 21: second slit.

Claims (2)

[Scope of utility model registration request] 1. A cylindrical body is divided into a plurality of pieces in the circumferential direction by leaving a plurality of slits extending in the axial direction while alternately leaving one end portion and the other end portion, and the other end portion from the one end to the other end portion of the inner circumference of the cylindrical body. The core shaft is provided with a collet main body formed by forming a pair of tapered holes that expand toward the ends, and a pair of tapered shaft parts that expand from the front end toward the rear part are formed at two locations in the axial direction of the front end part. A collet chuck provided with a pressing tool for fitting the collet main body to the mandrel, bringing each tapered hole into contact with each taper shaft portion of the mandrel, and pressing the collet main body in the rearward direction of the mandrel. A collet chuck characterized in that the outer diameter of both ends of the collet main body in which the tapered hole is located is formed to be slightly smaller than the outer diameter of the axial center portion of the collet main body. 2. The outer diameter of both ends of the collet main body in which each tapered hole is located is 0.
The collet chuck according to claim 1, wherein the collet chuck has a small diameter of 01 mm.